An embodiment of the inventive concept relates to a nonvolatile memory device, and, more particularly, to a nonvolatile memory device with a three-dimensional structure capable of improving electrical characteristics and a method of fabricating the same.
In general, nonvolatile memory devices can electrically erase and program data and can retain data even if power source is interrupted. Recently, nonvolatile memory devices are increasingly used in various fields.
These nonvolatile memory devices are provided with various types of memory cell transistors. The nonvolatile memory devices are classified into NAND type and NOR type according to cell array structures. The NAND-type flash memory devices and the NOR-type nonvolatile memory devices have both merits and demerits in high integration and high-speed performance, respectively.
Specifically, NAND-type flash memory devices may be advantageous for high integration due to a cell string structure in which a plurality of memory cell transistors is connected in series. In addition, because NAND-type flash memory devices use operations that simultaneously change all information stored in the plurality of memory cell transistors, information update speed of the NAND-type flash memory devices is generally far faster than that of the NOR-type nonvolatile memory device. Due to the high integration and fast update speed, NAND-type flash memory devices are mainly used for portable electronic products that require a mass storage device, such as a digital camera and an MP3 player.
Research and development efforts have been active in promoting and improving markedly the merits of NAND-type flash memory devices. Recent developments have been made with respect to NAND-type flash memory devices with a three-dimensional structure.